Ganeshalingam married Yamuna, daughter of Dr. Sri Pathmanathan.[1][4] They had a son (Kandeepan) and a daughter (Menaka).[3] Ganeshalingam was a Hindu.[2]
After university Ganeshalingam joined Ford Rhodes Thornton & Co as an accountancy student.[1][2] He then entered business.[1] He was director of the Tobacco Corporation and several other state organisations.[3] He was also chairman of Ceylon Oxygen.[3]
Ganeshalingam joined the United National Party (UNP) in 1960.[5] He was appointed treasurer of the UNP in 1989.[3][5][6] He was later elected to Colombo Municipal Council as a UNP candidate.[3] He served as Deputy Mayor of Colombo between July 1991 and the end of 1993.[2] He was acting Mayor of Colombo from January 1994 to June 1996 before serving as Mayor of Colombo between June 1996 and March 1997.[2][7] He resigned from the UNP in January 1997.[5][8] He then contested the 1997 election as a candidate of an independent group backed by the People's Alliance.[6][9] He was re-elected to CMC and served as Leader of the Opposition from May 1997 to April 2002.[3]
